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A. a.l SCHMIDT. Gig Sawing-Machi'nes.

Patehted May 5.18774.

AUG-UST (if. SCHMIDT, OF GREEN POINT, NEVIT YORK.

MPROVEMENT IN GG-SAWiNG MACHINES.

Specilieation forming pari of Letters Patent No. 150,487, dated May 5, 1h74; applicatinn filed Y February 10, 1874.

ATo all whom it may concern:

Be it known that I, AUGUs'L GEORGE SCHMTDT, of Green Point, in the county of Kings and State of New York, have invented a new and Improved Gig-sawing Machine, of

" which the following is a specification;

Figure l is a front elevation of my improved sawing-machine. Fig. 2 is a horizontal section of the same on the line c c, Fig. l; Fin'. 3, aV

single saws for purposes of scroll-sawing, or

other light or heavy work. My invention consists in an improved manner of adjusting the stain of the saw, and providing a strain-inrit cater; in a new adjustable center-pinefor circular cutting; and other improvements, all as hereinafter more fully described.

In the accompanying drawing, the letter A represents'the supporting frame-work of my sawing-machine. In the lower or any other part thereof is hung the drivin g-shaft B, which carriesl a wrist-pin, a., at one end, and is, by said wrist-pin and a pitman, b, connected with thelower slide d of the saw. C is the saw, provided with pins at its ends, so that it can be hooked into the two slides d and e in the customary manner. These slides work in proper guides f g, respectively, that are se-` cured to the frame A. The upper slide e I prefer to connect by a steel band, belt, or equivalent flexible strap, l), with the upper slide e* of another saw, 0*, at the opposite end of the frame A, the band or strap D passing over one or more rollers, h h, that hang in the frame A, as is clearly shown in Fig. 3. lf the second saw C* is, in the manner mentioned, connected with the sawO by the strap D, I prefer to also connect the lower slide d* of the saw C* by a pitman, bit, with a wrist-pin, at, at the opposite end of the shaft B, as shown, so that, by the shaft, both saws will be simultaneously operated in opposite directions. I believe this invention of working two saws that are connected like the heddles of a loom at their upper ends to be very advantageous, as it balances the power in a very satisfactory manner. The connection between the upper slide c and the band D is effected by a screw, c', a link-shaped nut, l, and a pin',j, as in Fig. l. The screw projects upwardl y from the slide cinto the nut. The pinj'is fastenedto the band D, and passes through the upper part of the nut, and has a head at its lower end. A spring, m, embraces the ping between the head of the same and the nut I, as shown. The more the nut is turned downward the more will the spring m be contracted, and the greater, therefore, the strain on the saw; while the strain on the saw is lessened by screwing the nut upward and expanding the spring. The spriu is ofk great use in straining the saw, as it is not rigid, but will yield if necessary. I have found that, for hard wood, the saw must be strained more than for soft; and, also, that the thicker the wood the greater should be the tension of thc saw. Therefore, in order to perform a certain kind of work with the saw, I must first adjust its tension accordingly. By the nut Z, I can easily do this; but, still, the nut alone would not be so very valuable, as it wouldrequire an expert hand to properly set it for every kind of work. I, therefore, in order to let boys or uneducated men manage the machine, apply a graduated scale to the side or face of the nut, as indicated at o 0 in Fig. 3. The head of the pinj will be the pointer for this scale.. It will now be easy to let every line of the scale stand for a particular thickness of particular kinds of wood, and to arrange tables or lists from which the adjustment will be a mere matter of copy. E is the presser-foot of the machine. This foot, in order to make it self-adjusting on uueven stuff, I have made with a hollow shank, p, and allowed it to slide on its stem r, a spring, s, bearing upon the shank. This spring holds the foot down upon the stuff, but allows it to yield upwardly if on thicker stuff. The stein or rod r, however, does not take part in this self-adjustability of the foot E, though it can, by set-screws, be secured in. a higher or lower position in the eyes t t of the frame that guide and hold it. The presser-foot, instead of being made sliding on the stem r, may be pivoted thereto, as in Fig. 4', the spring s, in that case, bearing against its heel to press it down,

but permitting it to swing upward and accommodate itself to a thicker board. The table is, in the drawing, shown to be in two partsone for each saw-the part F, for the saw G, being, by downwardly-proj eating lugs u u, and by pins fu t, pivoted in the frame A, so that it can be tilted, asin Fig. 3. This will enable the saw C to cut the stuft' at any desired angie to the surface. Finally, G is an attachment to the table F for facilitating the cutting yof circular shapes by the saw. This attachment consists of a shank or bar, which is secured upon the table, and carries a screw-pin, fw, that serves to center the stuff, as shown. By the screw-pin and an upward bend of the shank G,stu of suitable thickness can be centered, and the shank can be secured upon the table or to the frame in auy'suitable posi tion to bring the centering-pin w at suitable distance from the cutting-saw C, to enable the production of larger o r smaller circles.

I claim as my inventionl. The screw fi, nut l, pin j, and spring m., combined with the band D and saw-slide e, substantially as specified.

2. The presser-foot E for a saw, made selfadjusting by being fitted upon the stem r, and combined with the spring s, as set forth.

3. The centering attachment G w, arranged substantially as herein shown and described.

AUGUST GEORGE SCHMIDT.

Witnesses A. V. BRrEsEN, H. .EICKLING. 

